ПОЛУЧИТЬ метод для PHPExcel

Как я могу использовать метод GET для заполнения листа Excel с помощью PHPExcel.

В методе POST таблица Excel заполняется, но не в методе GET.

<?php
ob_start();
require_once 'Classes/PHPExcel.php';
require_once 'Classes/PHPExcel/IOFactory.php';
$name = $_GET['user_name'];
$mail = $_GET['user_email'];
$msg = $_GET['user_message'];
$to = 'theemailid';
$email_subject = "Excel Sheet:  $name";
$email_body = "You have received a new message from your website contact form.\n\n"."Here are the details:\n\nName: $name\n\nEmail: $mail\n\nMessage:$msg";
$headers = "From:theemailid\n";
$headers .= "Reply-To: $mail";
mail($to,$email_subject,$email_body,$headers);
$objPHPExcel = PHPExcel_IOFactory::load("excel.xlsx");
$objPHPExcel->setActiveSheetIndex(0);
$row = $objPHPExcel->getActiveSheet()->getHighestRow()+1;
date_default_timezone_set('Asia/Calcutta');
$date = date('Y-m-d h:i:s A');
$objPHPExcel->getActiveSheet()->SetCellValue('A'.$row, $date);
objPHPExcel->getActiveSheet()->SetCellValue('B'.$row,$_GET['user_name']);
$objPHPExcel->getActiveSheet()->SetCellValue('C'.$row, $_GET['user_email']);
$objPHPExcel->getActiveSheet()->SetCellValue('D'.$row, $_GET['user_message']);
$objWriter = new PHPExcel_Writer_Excel2007($objPHPExcel);
$objWriter->save("excel.xlsx");
?>